revision.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "blob.h"
   4 #include "tree.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "refs.h"
   8 #include "revision.h"
   9 #include "graph.h"
  10 #include "grep.h"
  11 #include "reflog-walk.h"
  12 #include "patch-ids.h"
  13 #include "decorate.h"
  14
  15 volatile show_early_output_fn_t show_early_output;
  16
  17 static char *path_name(struct name_path *path, const char *name)
  18 {
  19         struct name_path *p;
  20         char *n, *m;
  21         int nlen = strlen(name);
  22         int len = nlen + 1;
  23
  24         for (p = path; p; p = p->up) {
  25                 if (p->elem_len)
  26                         len += p->elem_len + 1;
  27         }
  28         n = xmalloc(len);
  29         m = n + len - (nlen + 1);
  30         strcpy(m, name);
  31         for (p = path; p; p = p->up) {
  32                 if (p->elem_len) {
  33                         m -= p->elem_len + 1;
  34                         memcpy(m, p->elem, p->elem_len);
  35                         m[p->elem_len] = '/';
  36                 }
  37         }
  38         return n;
  39 }
  40
  41 void add_object(struct object *obj,
  42                 struct object_array *p,
  43                 struct name_path *path,
  44                 const char *name)
  45 {
  46         add_object_array(obj, path_name(path, name), p);
  47 }
  48
  49 static void mark_blob_uninteresting(struct blob *blob)
  50 {
  51         if (!blob)
  52                 return;
  53         if (blob->object.flags & UNINTERESTING)
  54                 return;
  55         blob->object.flags |= UNINTERESTING;
  56 }
  57
  58 void mark_tree_uninteresting(struct tree *tree)
  59 {
  60         struct tree_desc desc;
  61         struct name_entry entry;
  62         struct object *obj = &tree->object;
  63
  64         if (!tree)
  65                 return;
  66         if (obj->flags & UNINTERESTING)
  67                 return;
  68         obj->flags |= UNINTERESTING;
  69         if (!has_sha1_file(obj->sha1))
  70                 return;
  71         if (parse_tree(tree) < 0)
  72                 die("bad tree %s", sha1_to_hex(obj->sha1));
  73
  74         init_tree_desc(&desc, tree->buffer, tree->size);
  75         while (tree_entry(&desc, &entry)) {
  76                 switch (object_type(entry.mode)) {
  77                 case OBJ_TREE:
  78                         mark_tree_uninteresting(lookup_tree(entry.sha1));
  79                         break;
  80                 case OBJ_BLOB:
  81                         mark_blob_uninteresting(lookup_blob(entry.sha1));
  82                         break;
  83                 default:
  84                         /* Subproject commit - not in this repository */
  85                         break;
  86                 }
  87         }
  88
  89         /*
  90          * We don't care about the tree any more
  91          * after it has been marked uninteresting.
  92          */
  93         free(tree->buffer);
  94         tree->buffer = NULL;
  95 }
  96
  97 void mark_parents_uninteresting(struct commit *commit)
  98 {
  99         struct commit_list *parents = commit->parents;
 100
 101         while (parents) {
 102                 struct commit *commit = parents->item;
 103                 if (!(commit->object.flags & UNINTERESTING)) {
 104                         commit->object.flags |= UNINTERESTING;
 105
 106                         /*
 107                          * Normally we haven't parsed the parent
 108                          * yet, so we won't have a parent of a parent
 109                          * here. However, it may turn out that we've
 110                          * reached this commit some other way (where it
 111                          * wasn't uninteresting), in which case we need
 112                          * to mark its parents recursively too..
 113                          */
 114                         if (commit->parents)
 115                                 mark_parents_uninteresting(commit);
 116                 }
 117
 118                 /*
 119                  * A missing commit is ok iff its parent is marked
 120                  * uninteresting.
 121                  *
 122                  * We just mark such a thing parsed, so that when
 123                  * it is popped next time around, we won't be trying
 124                  * to parse it and get an error.
 125                  */
 126                 if (!has_sha1_file(commit->object.sha1))
 127                         commit->object.parsed = 1;
 128                 parents = parents->next;
 129         }
 130 }
 131
 132 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 133 {
 134         if (revs->no_walk && (obj->flags & UNINTERESTING))
 135                 die("object ranges do not make sense when not walking revisions");
 136         if (revs->reflog_info && obj->type == OBJ_COMMIT &&
 137                         add_reflog_for_walk(revs->reflog_info,
 138                                 (struct commit *)obj, name))
 139                 return;
 140         add_object_array_with_mode(obj, name, &revs->pending, mode);
 141 }
 142
 143 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 144 {
 145         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 146 }
 147
 148 void add_head_to_pending(struct rev_info *revs)
 149 {
 150         unsigned char sha1[20];
 151         struct object *obj;
 152         if (get_sha1("HEAD", sha1))
 153                 return;
 154         obj = parse_object(sha1);
 155         if (!obj)
 156                 return;
 157         add_pending_object(revs, obj, "HEAD");
 158 }
 159
 160 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 161 {
 162         struct object *object;
 163
 164         object = parse_object(sha1);
 165         if (!object)
 166                 die("bad object %s", name);
 167         object->flags |= flags;
 168         return object;
 169 }
 170
 171 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 172 {
 173         unsigned long flags = object->flags;
 174
 175         /*
 176          * Tag object? Look what it points to..
 177          */
 178         while (object->type == OBJ_TAG) {
 179                 struct tag *tag = (struct tag *) object;
 180                 if (revs->tag_objects && !(flags & UNINTERESTING))
 181                         add_pending_object(revs, object, tag->tag);
 182                 if (!tag->tagged)
 183                         die("bad tag");
 184                 object = parse_object(tag->tagged->sha1);
 185                 if (!object)
 186                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 187         }
 188
 189         /*
 190          * Commit object? Just return it, we'll do all the complex
 191          * reachability crud.
 192          */
 193         if (object->type == OBJ_COMMIT) {
 194                 struct commit *commit = (struct commit *)object;
 195                 if (parse_commit(commit) < 0)
 196                         die("unable to parse commit %s", name);
 197                 if (flags & UNINTERESTING) {
 198                         commit->object.flags |= UNINTERESTING;
 199                         mark_parents_uninteresting(commit);
 200                         revs->limited = 1;
 201                 }
 202                 return commit;
 203         }
 204
 205         /*
 206          * Tree object? Either mark it uniniteresting, or add it
 207          * to the list of objects to look at later..
 208          */
 209         if (object->type == OBJ_TREE) {
 210                 struct tree *tree = (struct tree *)object;
 211                 if (!revs->tree_objects)
 212                         return NULL;
 213                 if (flags & UNINTERESTING) {
 214                         mark_tree_uninteresting(tree);
 215                         return NULL;
 216                 }
 217                 add_pending_object(revs, object, "");
 218                 return NULL;
 219         }
 220
 221         /*
 222          * Blob object? You know the drill by now..
 223          */
 224         if (object->type == OBJ_BLOB) {
 225                 struct blob *blob = (struct blob *)object;
 226                 if (!revs->blob_objects)
 227                         return NULL;
 228                 if (flags & UNINTERESTING) {
 229                         mark_blob_uninteresting(blob);
 230                         return NULL;
 231                 }
 232                 add_pending_object(revs, object, "");
 233                 return NULL;
 234         }
 235         die("%s is unknown object", name);
 236 }
 237
 238 static int everybody_uninteresting(struct commit_list *orig)
 239 {
 240         struct commit_list *list = orig;
 241         while (list) {
 242                 struct commit *commit = list->item;
 243                 list = list->next;
 244                 if (commit->object.flags & UNINTERESTING)
 245                         continue;
 246                 return 0;
 247         }
 248         return 1;
 249 }
 250
 251 /*
 252  * The goal is to get REV_TREE_NEW as the result only if the
 253  * diff consists of all '+' (and no other changes), and
 254  * REV_TREE_DIFFERENT otherwise (of course if the trees are
 255  * the same we want REV_TREE_SAME).  That means that once we
 256  * get to REV_TREE_DIFFERENT, we do not have to look any further.
 257  */
 258 static int tree_difference = REV_TREE_SAME;
 259
 260 static void file_add_remove(struct diff_options *options,
 261                     int addremove, unsigned mode,
 262                     const unsigned char *sha1,
 263                     const char *fullpath)
 264 {
 265         int diff = REV_TREE_DIFFERENT;
 266
 267         /*
 268          * Is it an add of a new file? It means that the old tree
 269          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 270          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 271          * (and if it already was "REV_TREE_NEW", we'll keep it
 272          * "REV_TREE_NEW" of course).
 273          */
 274         if (addremove == '+') {
 275                 diff = tree_difference;
 276                 if (diff != REV_TREE_SAME)
 277                         return;
 278                 diff = REV_TREE_NEW;
 279         }
 280         tree_difference = diff;
 281         if (tree_difference == REV_TREE_DIFFERENT)
 282                 DIFF_OPT_SET(options, HAS_CHANGES);
 283 }
 284
 285 static void file_change(struct diff_options *options,
 286                  unsigned old_mode, unsigned new_mode,
 287                  const unsigned char *old_sha1,
 288                  const unsigned char *new_sha1,
 289                  const char *fullpath)
 290 {
 291         tree_difference = REV_TREE_DIFFERENT;
 292         DIFF_OPT_SET(options, HAS_CHANGES);
 293 }
 294
 295 static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 296 {
 297         if (!t1)
 298                 return REV_TREE_NEW;
 299         if (!t2)
 300                 return REV_TREE_DIFFERENT;
 301         tree_difference = REV_TREE_SAME;
 302         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 303         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 304                            &revs->pruning) < 0)
 305                 return REV_TREE_DIFFERENT;
 306         return tree_difference;
 307 }
 308
 309 static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 310 {
 311         int retval;
 312         void *tree;
 313         unsigned long size;
 314         struct tree_desc empty, real;
 315
 316         if (!t1)
 317                 return 0;
 318
 319         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 320         if (!tree)
 321                 return 0;
 322         init_tree_desc(&real, tree, size);
 323         init_tree_desc(&empty, "", 0);
 324
 325         tree_difference = REV_TREE_SAME;
 326         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 327         retval = diff_tree(&empty, &real, "", &revs->pruning);
 328         free(tree);
 329
 330         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 331 }
 332
 333 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 334 {
 335         struct commit_list **pp, *parent;
 336         int tree_changed = 0, tree_same = 0;
 337
 338         /*
 339          * If we don't do pruning, everything is interesting
 340          */
 341         if (!revs->prune)
 342                 return;
 343
 344         if (!commit->tree)
 345                 return;
 346
 347         if (!commit->parents) {
 348                 if (rev_same_tree_as_empty(revs, commit->tree))
 349                         commit->object.flags |= TREESAME;
 350                 return;
 351         }
 352
 353         /*
 354          * Normal non-merge commit? If we don't want to make the
 355          * history dense, we consider it always to be a change..
 356          */
 357         if (!revs->dense && !commit->parents->next)
 358                 return;
 359
 360         pp = &commit->parents;
 361         while ((parent = *pp) != NULL) {
 362                 struct commit *p = parent->item;
 363
 364                 if (parse_commit(p) < 0)
 365                         die("cannot simplify commit %s (because of %s)",
 366                             sha1_to_hex(commit->object.sha1),
 367                             sha1_to_hex(p->object.sha1));
 368                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 369                 case REV_TREE_SAME:
 370                         tree_same = 1;
 371                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 372                                 /* Even if a merge with an uninteresting
 373                                  * side branch brought the entire change
 374                                  * we are interested in, we do not want
 375                                  * to lose the other branches of this
 376                                  * merge, so we just keep going.
 377                                  */
 378                                 pp = &parent->next;
 379                                 continue;
 380                         }
 381                         parent->next = NULL;
 382                         commit->parents = parent;
 383                         commit->object.flags |= TREESAME;
 384                         return;
 385
 386                 case REV_TREE_NEW:
 387                         if (revs->remove_empty_trees &&
 388                             rev_same_tree_as_empty(revs, p->tree)) {
 389                                 /* We are adding all the specified
 390                                  * paths from this parent, so the
 391                                  * history beyond this parent is not
 392                                  * interesting.  Remove its parents
 393                                  * (they are grandparents for us).
 394                                  * IOW, we pretend this parent is a
 395                                  * "root" commit.
 396                                  */
 397                                 if (parse_commit(p) < 0)
 398                                         die("cannot simplify commit %s (invalid %s)",
 399                                             sha1_to_hex(commit->object.sha1),
 400                                             sha1_to_hex(p->object.sha1));
 401                                 p->parents = NULL;
 402                         }
 403                 /* fallthrough */
 404                 case REV_TREE_DIFFERENT:
 405                         tree_changed = 1;
 406                         pp = &parent->next;
 407                         continue;
 408                 }
 409                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 410         }
 411         if (tree_changed && !tree_same)
 412                 return;
 413         commit->object.flags |= TREESAME;
 414 }
 415
 416 static void insert_by_date_cached(struct commit *p, struct commit_list **head,
 417                     struct commit_list *cached_base, struct commit_list **cache)
 418 {
 419         struct commit_list *new_entry;
 420
 421         if (cached_base && p->date < cached_base->item->date)
 422                 new_entry = insert_by_date(p, &cached_base->next);
 423         else
 424                 new_entry = insert_by_date(p, head);
 425
 426         if (cache && (!*cache || p->date < (*cache)->item->date))
 427                 *cache = new_entry;
 428 }
 429
 430 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 431                     struct commit_list **list, struct commit_list **cache_ptr)
 432 {
 433         struct commit_list *parent = commit->parents;
 434         unsigned left_flag;
 435         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 436
 437         if (commit->object.flags & ADDED)
 438                 return 0;
 439         commit->object.flags |= ADDED;
 440
 441         /*
 442          * If the commit is uninteresting, don't try to
 443          * prune parents - we want the maximal uninteresting
 444          * set.
 445          *
 446          * Normally we haven't parsed the parent
 447          * yet, so we won't have a parent of a parent
 448          * here. However, it may turn out that we've
 449          * reached this commit some other way (where it
 450          * wasn't uninteresting), in which case we need
 451          * to mark its parents recursively too..
 452          */
 453         if (commit->object.flags & UNINTERESTING) {
 454                 while (parent) {
 455                         struct commit *p = parent->item;
 456                         parent = parent->next;
 457                         if (parse_commit(p) < 0)
 458                                 return -1;
 459                         p->object.flags |= UNINTERESTING;
 460                         if (p->parents)
 461                                 mark_parents_uninteresting(p);
 462                         if (p->object.flags & SEEN)
 463                                 continue;
 464                         p->object.flags |= SEEN;
 465                         insert_by_date_cached(p, list, cached_base, cache_ptr);
 466                 }
 467                 return 0;
 468         }
 469
 470         /*
 471          * Ok, the commit wasn't uninteresting. Try to
 472          * simplify the commit history and find the parent
 473          * that has no differences in the path set if one exists.
 474          */
 475         try_to_simplify_commit(revs, commit);
 476
 477         if (revs->no_walk)
 478                 return 0;
 479
 480         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 481
 482         for (parent = commit->parents; parent; parent = parent->next) {
 483                 struct commit *p = parent->item;
 484
 485                 if (parse_commit(p) < 0)
 486                         return -1;
 487                 p->object.flags |= left_flag;
 488                 if (!(p->object.flags & SEEN)) {
 489                         p->object.flags |= SEEN;
 490                         insert_by_date_cached(p, list, cached_base, cache_ptr);
 491                 }
 492                 if(revs->first_parent_only)
 493                         break;
 494         }
 495         return 0;
 496 }
 497
 498 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 499 {
 500         struct commit_list *p;
 501         int left_count = 0, right_count = 0;
 502         int left_first;
 503         struct patch_ids ids;
 504
 505         /* First count the commits on the left and on the right */
 506         for (p = list; p; p = p->next) {
 507                 struct commit *commit = p->item;
 508                 unsigned flags = commit->object.flags;
 509                 if (flags & BOUNDARY)
 510                         ;
 511                 else if (flags & SYMMETRIC_LEFT)
 512                         left_count++;
 513                 else
 514                         right_count++;
 515         }
 516
 517         left_first = left_count < right_count;
 518         init_patch_ids(&ids);
 519         if (revs->diffopt.nr_paths) {
 520                 ids.diffopts.nr_paths = revs->diffopt.nr_paths;
 521                 ids.diffopts.paths = revs->diffopt.paths;
 522                 ids.diffopts.pathlens = revs->diffopt.pathlens;
 523         }
 524
 525         /* Compute patch-ids for one side */
 526         for (p = list; p; p = p->next) {
 527                 struct commit *commit = p->item;
 528                 unsigned flags = commit->object.flags;
 529
 530                 if (flags & BOUNDARY)
 531                         continue;
 532                 /*
 533                  * If we have fewer left, left_first is set and we omit
 534                  * commits on the right branch in this loop.  If we have
 535                  * fewer right, we skip the left ones.
 536                  */
 537                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 538                         continue;
 539                 commit->util = add_commit_patch_id(commit, &ids);
 540         }
 541
 542         /* Check the other side */
 543         for (p = list; p; p = p->next) {
 544                 struct commit *commit = p->item;
 545                 struct patch_id *id;
 546                 unsigned flags = commit->object.flags;
 547
 548                 if (flags & BOUNDARY)
 549                         continue;
 550                 /*
 551                  * If we have fewer left, left_first is set and we omit
 552                  * commits on the left branch in this loop.
 553                  */
 554                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 555                         continue;
 556
 557                 /*
 558                  * Have we seen the same patch id?
 559                  */
 560                 id = has_commit_patch_id(commit, &ids);
 561                 if (!id)
 562                         continue;
 563                 id->seen = 1;
 564                 commit->object.flags |= SHOWN;
 565         }
 566
 567         /* Now check the original side for seen ones */
 568         for (p = list; p; p = p->next) {
 569                 struct commit *commit = p->item;
 570                 struct patch_id *ent;
 571
 572                 ent = commit->util;
 573                 if (!ent)
 574                         continue;
 575                 if (ent->seen)
 576                         commit->object.flags |= SHOWN;
 577                 commit->util = NULL;
 578         }
 579
 580         free_patch_ids(&ids);
 581 }
 582
 583 /* How many extra uninteresting commits we want to see.. */
 584 #define SLOP 5
 585
 586 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 587 {
 588         /*
 589          * No source list at all? We're definitely done..
 590          */
 591         if (!src)
 592                 return 0;
 593
 594         /*
 595          * Does the destination list contain entries with a date
 596          * before the source list? Definitely _not_ done.
 597          */
 598         if (date < src->item->date)
 599                 return SLOP;
 600
 601         /*
 602          * Does the source list still have interesting commits in
 603          * it? Definitely not done..
 604          */
 605         if (!everybody_uninteresting(src))
 606                 return SLOP;
 607
 608         /* Ok, we're closing in.. */
 609         return slop-1;
 610 }
 611
 612 static int limit_list(struct rev_info *revs)
 613 {
 614         int slop = SLOP;
 615         unsigned long date = ~0ul;
 616         struct commit_list *list = revs->commits;
 617         struct commit_list *newlist = NULL;
 618         struct commit_list **p = &newlist;
 619
 620         while (list) {
 621                 struct commit_list *entry = list;
 622                 struct commit *commit = list->item;
 623                 struct object *obj = &commit->object;
 624                 show_early_output_fn_t show;
 625
 626                 list = list->next;
 627                 free(entry);
 628
 629                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 630                         obj->flags |= UNINTERESTING;
 631                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 632                         return -1;
 633                 if (obj->flags & UNINTERESTING) {
 634                         mark_parents_uninteresting(commit);
 635                         if (revs->show_all)
 636                                 p = &commit_list_insert(commit, p)->next;
 637                         slop = still_interesting(list, date, slop);
 638                         if (slop)
 639                                 continue;
 640                         /* If showing all, add the whole pending list to the end */
 641                         if (revs->show_all)
 642                                 *p = list;
 643                         break;
 644                 }
 645                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 646                         continue;
 647                 date = commit->date;
 648                 p = &commit_list_insert(commit, p)->next;
 649
 650                 show = show_early_output;
 651                 if (!show)
 652                         continue;
 653
 654                 show(revs, newlist);
 655                 show_early_output = NULL;
 656         }
 657         if (revs->cherry_pick)
 658                 cherry_pick_list(newlist, revs);
 659
 660         revs->commits = newlist;
 661         return 0;
 662 }
 663
 664 struct all_refs_cb {
 665         int all_flags;
 666         int warned_bad_reflog;
 667         struct rev_info *all_revs;
 668         const char *name_for_errormsg;
 669 };
 670
 671 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 672 {
 673         struct all_refs_cb *cb = cb_data;
 674         struct object *object = get_reference(cb->all_revs, path, sha1,
 675                                               cb->all_flags);
 676         add_pending_object(cb->all_revs, object, path);
 677         return 0;
 678 }
 679
 680 static void handle_refs(struct rev_info *revs, unsigned flags,
 681                 int (*for_each)(each_ref_fn, void *))
 682 {
 683         struct all_refs_cb cb;
 684         cb.all_revs = revs;
 685         cb.all_flags = flags;
 686         for_each(handle_one_ref, &cb);
 687 }
 688
 689 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 690 {
 691         struct all_refs_cb *cb = cb_data;
 692         if (!is_null_sha1(sha1)) {
 693                 struct object *o = parse_object(sha1);
 694                 if (o) {
 695                         o->flags |= cb->all_flags;
 696                         add_pending_object(cb->all_revs, o, "");
 697                 }
 698                 else if (!cb->warned_bad_reflog) {
 699                         warning("reflog of '%s' references pruned commits",
 700                                 cb->name_for_errormsg);
 701                         cb->warned_bad_reflog = 1;
 702                 }
 703         }
 704 }
 705
 706 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 707                 const char *email, unsigned long timestamp, int tz,
 708                 const char *message, void *cb_data)
 709 {
 710         handle_one_reflog_commit(osha1, cb_data);
 711         handle_one_reflog_commit(nsha1, cb_data);
 712         return 0;
 713 }
 714
 715 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 716 {
 717         struct all_refs_cb *cb = cb_data;
 718         cb->warned_bad_reflog = 0;
 719         cb->name_for_errormsg = path;
 720         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 721         return 0;
 722 }
 723
 724 static void handle_reflog(struct rev_info *revs, unsigned flags)
 725 {
 726         struct all_refs_cb cb;
 727         cb.all_revs = revs;
 728         cb.all_flags = flags;
 729         for_each_reflog(handle_one_reflog, &cb);
 730 }
 731
 732 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 733 {
 734         unsigned char sha1[20];
 735         struct object *it;
 736         struct commit *commit;
 737         struct commit_list *parents;
 738
 739         if (*arg == '^') {
 740                 flags ^= UNINTERESTING;
 741                 arg++;
 742         }
 743         if (get_sha1(arg, sha1))
 744                 return 0;
 745         while (1) {
 746                 it = get_reference(revs, arg, sha1, 0);
 747                 if (it->type != OBJ_TAG)
 748                         break;
 749                 if (!((struct tag*)it)->tagged)
 750                         return 0;
 751                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 752         }
 753         if (it->type != OBJ_COMMIT)
 754                 return 0;
 755         commit = (struct commit *)it;
 756         for (parents = commit->parents; parents; parents = parents->next) {
 757                 it = &parents->item->object;
 758                 it->flags |= flags;
 759                 add_pending_object(revs, it, arg);
 760         }
 761         return 1;
 762 }
 763
 764 void init_revisions(struct rev_info *revs, const char *prefix)
 765 {
 766         memset(revs, 0, sizeof(*revs));
 767
 768         revs->abbrev = DEFAULT_ABBREV;
 769         revs->ignore_merges = 1;
 770         revs->simplify_history = 1;
 771         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 772         DIFF_OPT_SET(&revs->pruning, QUIET);
 773         revs->pruning.add_remove = file_add_remove;
 774         revs->pruning.change = file_change;
 775         revs->lifo = 1;
 776         revs->dense = 1;
 777         revs->prefix = prefix;
 778         revs->max_age = -1;
 779         revs->min_age = -1;
 780         revs->skip_count = -1;
 781         revs->max_count = -1;
 782
 783         revs->commit_format = CMIT_FMT_DEFAULT;
 784
 785         revs->grep_filter.status_only = 1;
 786         revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
 787         revs->grep_filter.regflags = REG_NEWLINE;
 788
 789         diff_setup(&revs->diffopt);
 790         if (prefix && !revs->diffopt.prefix) {
 791                 revs->diffopt.prefix = prefix;
 792                 revs->diffopt.prefix_length = strlen(prefix);
 793         }
 794 }
 795
 796 static void add_pending_commit_list(struct rev_info *revs,
 797                                     struct commit_list *commit_list,
 798                                     unsigned int flags)
 799 {
 800         while (commit_list) {
 801                 struct object *object = &commit_list->item->object;
 802                 object->flags |= flags;
 803                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 804                 commit_list = commit_list->next;
 805         }
 806 }
 807
 808 static void prepare_show_merge(struct rev_info *revs)
 809 {
 810         struct commit_list *bases;
 811         struct commit *head, *other;
 812         unsigned char sha1[20];
 813         const char **prune = NULL;
 814         int i, prune_num = 1; /* counting terminating NULL */
 815
 816         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 817                 die("--merge without HEAD?");
 818         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 819                 die("--merge without MERGE_HEAD?");
 820         add_pending_object(revs, &head->object, "HEAD");
 821         add_pending_object(revs, &other->object, "MERGE_HEAD");
 822         bases = get_merge_bases(head, other, 1);
 823         add_pending_commit_list(revs, bases, UNINTERESTING);
 824         free_commit_list(bases);
 825         head->object.flags |= SYMMETRIC_LEFT;
 826
 827         if (!active_nr)
 828                 read_cache();
 829         for (i = 0; i < active_nr; i++) {
 830                 struct cache_entry *ce = active_cache[i];
 831                 if (!ce_stage(ce))
 832                         continue;
 833                 if (ce_path_match(ce, revs->prune_data)) {
 834                         prune_num++;
 835                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 836                         prune[prune_num-2] = ce->name;
 837                         prune[prune_num-1] = NULL;
 838                 }
 839                 while ((i+1 < active_nr) &&
 840                        ce_same_name(ce, active_cache[i+1]))
 841                         i++;
 842         }
 843         revs->prune_data = prune;
 844         revs->limited = 1;
 845 }
 846
 847 int handle_revision_arg(const char *arg, struct rev_info *revs,
 848                         int flags,
 849                         int cant_be_filename)
 850 {
 851         unsigned mode;
 852         char *dotdot;
 853         struct object *object;
 854         unsigned char sha1[20];
 855         int local_flags;
 856
 857         dotdot = strstr(arg, "..");
 858         if (dotdot) {
 859                 unsigned char from_sha1[20];
 860                 const char *next = dotdot + 2;
 861                 const char *this = arg;
 862                 int symmetric = *next == '.';
 863                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 864
 865                 *dotdot = 0;
 866                 next += symmetric;
 867
 868                 if (!*next)
 869                         next = "HEAD";
 870                 if (dotdot == arg)
 871                         this = "HEAD";
 872                 if (!get_sha1(this, from_sha1) &&
 873                     !get_sha1(next, sha1)) {
 874                         struct commit *a, *b;
 875                         struct commit_list *exclude;
 876
 877                         a = lookup_commit_reference(from_sha1);
 878                         b = lookup_commit_reference(sha1);
 879                         if (!a || !b) {
 880                                 die(symmetric ?
 881                                     "Invalid symmetric difference expression %s...%s" :
 882                                     "Invalid revision range %s..%s",
 883                                     arg, next);
 884                         }
 885
 886                         if (!cant_be_filename) {
 887                                 *dotdot = '.';
 888                                 verify_non_filename(revs->prefix, arg);
 889                         }
 890
 891                         if (symmetric) {
 892                                 exclude = get_merge_bases(a, b, 1);
 893                                 add_pending_commit_list(revs, exclude,
 894                                                         flags_exclude);
 895                                 free_commit_list(exclude);
 896                                 a->object.flags |= flags | SYMMETRIC_LEFT;
 897                         } else
 898                                 a->object.flags |= flags_exclude;
 899                         b->object.flags |= flags;
 900                         add_pending_object(revs, &a->object, this);
 901                         add_pending_object(revs, &b->object, next);
 902                         return 0;
 903                 }
 904                 *dotdot = '.';
 905         }
 906         dotdot = strstr(arg, "^@");
 907         if (dotdot && !dotdot[2]) {
 908                 *dotdot = 0;
 909                 if (add_parents_only(revs, arg, flags))
 910                         return 0;
 911                 *dotdot = '^';
 912         }
 913         dotdot = strstr(arg, "^!");
 914         if (dotdot && !dotdot[2]) {
 915                 *dotdot = 0;
 916                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 917                         *dotdot = '^';
 918         }
 919
 920         local_flags = 0;
 921         if (*arg == '^') {
 922                 local_flags = UNINTERESTING;
 923                 arg++;
 924         }
 925         if (get_sha1_with_mode(arg, sha1, &mode))
 926                 return -1;
 927         if (!cant_be_filename)
 928                 verify_non_filename(revs->prefix, arg);
 929         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 930         add_pending_object_with_mode(revs, object, arg, mode);
 931         return 0;
 932 }
 933
 934 void read_revisions_from_stdin(struct rev_info *revs)
 935 {
 936         char line[1000];
 937
 938         while (fgets(line, sizeof(line), stdin) != NULL) {
 939                 int len = strlen(line);
 940                 if (len && line[len - 1] == '\n')
 941                         line[--len] = '\0';
 942                 if (!len)
 943                         break;
 944                 if (line[0] == '-')
 945                         die("options not supported in --stdin mode");
 946                 if (handle_revision_arg(line, revs, 0, 1))
 947                         die("bad revision '%s'", line);
 948         }
 949 }
 950
 951 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 952 {
 953         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
 954 }
 955
 956 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 957 {
 958         char *pat;
 959         const char *prefix;
 960         int patlen, fldlen;
 961
 962         fldlen = strlen(field);
 963         patlen = strlen(pattern);
 964         pat = xmalloc(patlen + fldlen + 10);
 965         prefix = ".*";
 966         if (*pattern == '^') {
 967                 prefix = "";
 968                 pattern++;
 969         }
 970         sprintf(pat, "^%s %s%s", field, prefix, pattern);
 971         add_grep(revs, pat, GREP_PATTERN_HEAD);
 972 }
 973
 974 static void add_message_grep(struct rev_info *revs, const char *pattern)
 975 {
 976         add_grep(revs, pattern, GREP_PATTERN_BODY);
 977 }
 978
 979 static void add_ignore_packed(struct rev_info *revs, const char *name)
 980 {
 981         int num = ++revs->num_ignore_packed;
 982
 983         revs->ignore_packed = xrealloc(revs->ignore_packed,
 984                                        sizeof(const char **) * (num + 1));
 985         revs->ignore_packed[num-1] = name;
 986         revs->ignore_packed[num] = NULL;
 987 }
 988
 989 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
 990                                int *unkc, const char **unkv)
 991 {
 992         const char *arg = argv[0];
 993
 994         /* pseudo revision arguments */
 995         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
 996             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
 997             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
 998             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk"))
 999         {
1000                 unkv[(*unkc)++] = arg;
1001                 return 1;
1002         }
1003
1004         if (!prefixcmp(arg, "--max-count=")) {
1005                 revs->max_count = atoi(arg + 12);
1006         } else if (!prefixcmp(arg, "--skip=")) {
1007                 revs->skip_count = atoi(arg + 7);
1008         } else if ((*arg == '-') && isdigit(arg[1])) {
1009         /* accept -<digit>, like traditional "head" */
1010                 revs->max_count = atoi(arg + 1);
1011         } else if (!strcmp(arg, "-n")) {
1012                 if (argc <= 1)
1013                         return error("-n requires an argument");
1014                 revs->max_count = atoi(argv[1]);
1015                 return 2;
1016         } else if (!prefixcmp(arg, "-n")) {
1017                 revs->max_count = atoi(arg + 2);
1018         } else if (!prefixcmp(arg, "--max-age=")) {
1019                 revs->max_age = atoi(arg + 10);
1020         } else if (!prefixcmp(arg, "--since=")) {
1021                 revs->max_age = approxidate(arg + 8);
1022         } else if (!prefixcmp(arg, "--after=")) {
1023                 revs->max_age = approxidate(arg + 8);
1024         } else if (!prefixcmp(arg, "--min-age=")) {
1025                 revs->min_age = atoi(arg + 10);
1026         } else if (!prefixcmp(arg, "--before=")) {
1027                 revs->min_age = approxidate(arg + 9);
1028         } else if (!prefixcmp(arg, "--until=")) {
1029                 revs->min_age = approxidate(arg + 8);
1030         } else if (!strcmp(arg, "--first-parent")) {
1031                 revs->first_parent_only = 1;
1032         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1033                 init_reflog_walk(&revs->reflog_info);
1034         } else if (!strcmp(arg, "--default")) {
1035                 if (argc <= 1)
1036                         return error("bad --default argument");
1037                 revs->def = argv[1];
1038                 return 2;
1039         } else if (!strcmp(arg, "--merge")) {
1040                 revs->show_merge = 1;
1041         } else if (!strcmp(arg, "--topo-order")) {
1042                 revs->lifo = 1;
1043                 revs->topo_order = 1;
1044         } else if (!strcmp(arg, "--date-order")) {
1045                 revs->lifo = 0;
1046                 revs->topo_order = 1;
1047         } else if (!prefixcmp(arg, "--early-output")) {
1048                 int count = 100;
1049                 switch (arg[14]) {
1050                 case '=':
1051                         count = atoi(arg+15);
1052                         /* Fallthrough */
1053                 case 0:
1054                         revs->topo_order = 1;
1055                        revs->early_output = count;
1056                 }
1057         } else if (!strcmp(arg, "--parents")) {
1058                 revs->rewrite_parents = 1;
1059                 revs->print_parents = 1;
1060         } else if (!strcmp(arg, "--dense")) {
1061                 revs->dense = 1;
1062         } else if (!strcmp(arg, "--sparse")) {
1063                 revs->dense = 0;
1064         } else if (!strcmp(arg, "--show-all")) {
1065                 revs->show_all = 1;
1066         } else if (!strcmp(arg, "--remove-empty")) {
1067                 revs->remove_empty_trees = 1;
1068         } else if (!strcmp(arg, "--no-merges")) {
1069                 revs->no_merges = 1;
1070         } else if (!strcmp(arg, "--boundary")) {
1071                 revs->boundary = 1;
1072         } else if (!strcmp(arg, "--left-right")) {
1073                 revs->left_right = 1;
1074         } else if (!strcmp(arg, "--cherry-pick")) {
1075                 revs->cherry_pick = 1;
1076                 revs->limited = 1;
1077         } else if (!strcmp(arg, "--objects")) {
1078                 revs->tag_objects = 1;
1079                 revs->tree_objects = 1;
1080                 revs->blob_objects = 1;
1081         } else if (!strcmp(arg, "--objects-edge")) {
1082                 revs->tag_objects = 1;
1083                 revs->tree_objects = 1;
1084                 revs->blob_objects = 1;
1085                 revs->edge_hint = 1;
1086         } else if (!strcmp(arg, "--unpacked")) {
1087                 revs->unpacked = 1;
1088                 free(revs->ignore_packed);
1089                 revs->ignore_packed = NULL;
1090                 revs->num_ignore_packed = 0;
1091         } else if (!prefixcmp(arg, "--unpacked=")) {
1092                 revs->unpacked = 1;
1093                 add_ignore_packed(revs, arg+11);
1094         } else if (!strcmp(arg, "-r")) {
1095                 revs->diff = 1;
1096                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1097         } else if (!strcmp(arg, "-t")) {
1098                 revs->diff = 1;
1099                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1100                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1101         } else if (!strcmp(arg, "-m")) {
1102                 revs->ignore_merges = 0;
1103         } else if (!strcmp(arg, "-c")) {
1104                 revs->diff = 1;
1105                 revs->dense_combined_merges = 0;
1106                 revs->combine_merges = 1;
1107         } else if (!strcmp(arg, "--cc")) {
1108                 revs->diff = 1;
1109                 revs->dense_combined_merges = 1;
1110                 revs->combine_merges = 1;
1111         } else if (!strcmp(arg, "-v")) {
1112                 revs->verbose_header = 1;
1113         } else if (!strcmp(arg, "--pretty")) {
1114                 revs->verbose_header = 1;
1115                 get_commit_format(arg+8, revs);
1116         } else if (!prefixcmp(arg, "--pretty=")) {
1117                 revs->verbose_header = 1;
1118                 get_commit_format(arg+9, revs);
1119         } else if (!strcmp(arg, "--graph")) {
1120                 revs->topo_order = 1;
1121                 revs->rewrite_parents = 1;
1122                 revs->graph = graph_init(revs);
1123         } else if (!strcmp(arg, "--root")) {
1124                 revs->show_root_diff = 1;
1125         } else if (!strcmp(arg, "--no-commit-id")) {
1126                 revs->no_commit_id = 1;
1127         } else if (!strcmp(arg, "--always")) {
1128                 revs->always_show_header = 1;
1129         } else if (!strcmp(arg, "--no-abbrev")) {
1130                 revs->abbrev = 0;
1131         } else if (!strcmp(arg, "--abbrev")) {
1132                 revs->abbrev = DEFAULT_ABBREV;
1133         } else if (!prefixcmp(arg, "--abbrev=")) {
1134                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1135                 if (revs->abbrev < MINIMUM_ABBREV)
1136                         revs->abbrev = MINIMUM_ABBREV;
1137                 else if (revs->abbrev > 40)
1138                         revs->abbrev = 40;
1139         } else if (!strcmp(arg, "--abbrev-commit")) {
1140                 revs->abbrev_commit = 1;
1141         } else if (!strcmp(arg, "--full-diff")) {
1142                 revs->diff = 1;
1143                 revs->full_diff = 1;
1144         } else if (!strcmp(arg, "--full-history")) {
1145                 revs->simplify_history = 0;
1146         } else if (!strcmp(arg, "--relative-date")) {
1147                 revs->date_mode = DATE_RELATIVE;
1148         } else if (!strncmp(arg, "--date=", 7)) {
1149                 revs->date_mode = parse_date_format(arg + 7);
1150         } else if (!strcmp(arg, "--log-size")) {
1151                 revs->show_log_size = 1;
1152         }
1153         /*
1154          * Grepping the commit log
1155          */
1156         else if (!prefixcmp(arg, "--author=")) {
1157                 add_header_grep(revs, "author", arg+9);
1158         } else if (!prefixcmp(arg, "--committer=")) {
1159                 add_header_grep(revs, "committer", arg+12);
1160         } else if (!prefixcmp(arg, "--grep=")) {
1161                 add_message_grep(revs, arg+7);
1162         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1163                 revs->grep_filter.regflags |= REG_EXTENDED;
1164         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1165                 revs->grep_filter.regflags |= REG_ICASE;
1166         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1167                 revs->grep_filter.fixed = 1;
1168         } else if (!strcmp(arg, "--all-match")) {
1169                 revs->grep_filter.all_match = 1;
1170         } else if (!prefixcmp(arg, "--encoding=")) {
1171                 arg += 11;
1172                 if (strcmp(arg, "none"))
1173                         git_log_output_encoding = xstrdup(arg);
1174                 else
1175                         git_log_output_encoding = "";
1176         } else if (!strcmp(arg, "--reverse")) {
1177                 revs->reverse ^= 1;
1178         } else if (!strcmp(arg, "--children")) {
1179                 revs->children.name = "children";
1180                 revs->limited = 1;
1181         } else {
1182                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1183                 if (!opts)
1184                         unkv[(*unkc)++] = arg;
1185                 return opts;
1186         }
1187
1188         return 1;
1189 }
1190
1191 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1192                         const struct option *options,
1193                         const char * const usagestr[])
1194 {
1195         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1196                                     &ctx->cpidx, ctx->out);
1197         if (n <= 0) {
1198                 error("unknown option `%s'", ctx->argv[0]);
1199                 usage_with_options(usagestr, options);
1200         }
1201         ctx->argv += n;
1202         ctx->argc -= n;
1203 }
1204
1205 /*
1206  * Parse revision information, filling in the "rev_info" structure,
1207  * and removing the used arguments from the argument list.
1208  *
1209  * Returns the number of arguments left that weren't recognized
1210  * (which are also moved to the head of the argument list)
1211  */
1212 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
1213 {
1214         int i, flags, left, seen_dashdash;
1215
1216         /* First, search for "--" */
1217         seen_dashdash = 0;
1218         for (i = 1; i < argc; i++) {
1219                 const char *arg = argv[i];
1220                 if (strcmp(arg, "--"))
1221                         continue;
1222                 argv[i] = NULL;
1223                 argc = i;
1224                 if (argv[i + 1])
1225                         revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
1226                 seen_dashdash = 1;
1227                 break;
1228         }
1229
1230         /* Second, deal with arguments and options */
1231         flags = 0;
1232         for (left = i = 1; i < argc; i++) {
1233                 const char *arg = argv[i];
1234                 if (*arg == '-') {
1235                         int opts;
1236
1237                         if (!strcmp(arg, "--all")) {
1238                                 handle_refs(revs, flags, for_each_ref);
1239                                 continue;
1240                         }
1241                         if (!strcmp(arg, "--branches")) {
1242                                 handle_refs(revs, flags, for_each_branch_ref);
1243                                 continue;
1244                         }
1245                         if (!strcmp(arg, "--tags")) {
1246                                 handle_refs(revs, flags, for_each_tag_ref);
1247                                 continue;
1248                         }
1249                         if (!strcmp(arg, "--remotes")) {
1250                                 handle_refs(revs, flags, for_each_remote_ref);
1251                                 continue;
1252                         }
1253                         if (!strcmp(arg, "--reflog")) {
1254                                 handle_reflog(revs, flags);
1255                                 continue;
1256                         }
1257                         if (!strcmp(arg, "--not")) {
1258                                 flags ^= UNINTERESTING;
1259                                 continue;
1260                         }
1261                         if (!strcmp(arg, "--no-walk")) {
1262                                 revs->no_walk = 1;
1263                                 continue;
1264                         }
1265                         if (!strcmp(arg, "--do-walk")) {
1266                                 revs->no_walk = 0;
1267                                 continue;
1268                         }
1269
1270                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1271                         if (opts > 0) {
1272                                 i += opts - 1;
1273                                 continue;
1274                         }
1275                         if (opts < 0)
1276                                 exit(128);
1277                         continue;
1278                 }
1279
1280                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1281                         int j;
1282                         if (seen_dashdash || *arg == '^')
1283                                 die("bad revision '%s'", arg);
1284
1285                         /* If we didn't have a "--":
1286                          * (1) all filenames must exist;
1287                          * (2) all rev-args must not be interpretable
1288                          *     as a valid filename.
1289                          * but the latter we have checked in the main loop.
1290                          */
1291                         for (j = i; j < argc; j++)
1292                                 verify_filename(revs->prefix, argv[j]);
1293
1294                         revs->prune_data = get_pathspec(revs->prefix,
1295                                                         argv + i);
1296                         break;
1297                 }
1298         }
1299
1300         if (revs->def == NULL)
1301                 revs->def = def;
1302         if (revs->show_merge)
1303                 prepare_show_merge(revs);
1304         if (revs->def && !revs->pending.nr) {
1305                 unsigned char sha1[20];
1306                 struct object *object;
1307                 unsigned mode;
1308                 if (get_sha1_with_mode(revs->def, sha1, &mode))
1309                         die("bad default revision '%s'", revs->def);
1310                 object = get_reference(revs, revs->def, sha1, 0);
1311                 add_pending_object_with_mode(revs, object, revs->def, mode);
1312         }
1313
1314         /* Did the user ask for any diff output? Run the diff! */
1315         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1316                 revs->diff = 1;
1317
1318         /* Pickaxe, diff-filter and rename following need diffs */
1319         if (revs->diffopt.pickaxe ||
1320             revs->diffopt.filter ||
1321             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1322                 revs->diff = 1;
1323
1324         if (revs->topo_order)
1325                 revs->limited = 1;
1326
1327         if (revs->prune_data) {
1328                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1329                 /* Can't prune commits with rename following: the paths change.. */
1330                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1331                         revs->prune = 1;
1332                 if (!revs->full_diff)
1333                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1334         }
1335         if (revs->combine_merges) {
1336                 revs->ignore_merges = 0;
1337                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1338                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1339         }
1340         revs->diffopt.abbrev = revs->abbrev;
1341         if (diff_setup_done(&revs->diffopt) < 0)
1342                 die("diff_setup_done failed");
1343
1344         compile_grep_patterns(&revs->grep_filter);
1345
1346         if (revs->reverse && revs->reflog_info)
1347                 die("cannot combine --reverse with --walk-reflogs");
1348         if (revs->rewrite_parents && revs->children.name)
1349                 die("cannot combine --parents and --children");
1350
1351         /*
1352          * Limitations on the graph functionality
1353          */
1354         if (revs->reverse && revs->graph)
1355                 die("cannot combine --reverse with --graph");
1356
1357         if (revs->reflog_info && revs->graph)
1358                 die("cannot combine --walk-reflogs with --graph");
1359
1360         return left;
1361 }
1362
1363 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1364 {
1365         struct commit_list *l = xcalloc(1, sizeof(*l));
1366
1367         l->item = child;
1368         l->next = add_decoration(&revs->children, &parent->object, l);
1369 }
1370
1371 static void set_children(struct rev_info *revs)
1372 {
1373         struct commit_list *l;
1374         for (l = revs->commits; l; l = l->next) {
1375                 struct commit *commit = l->item;
1376                 struct commit_list *p;
1377
1378                 for (p = commit->parents; p; p = p->next)
1379                         add_child(revs, p->item, commit);
1380         }
1381 }
1382
1383 int prepare_revision_walk(struct rev_info *revs)
1384 {
1385         int nr = revs->pending.nr;
1386         struct object_array_entry *e, *list;
1387
1388         e = list = revs->pending.objects;
1389         revs->pending.nr = 0;
1390         revs->pending.alloc = 0;
1391         revs->pending.objects = NULL;
1392         while (--nr >= 0) {
1393                 struct commit *commit = handle_commit(revs, e->item, e->name);
1394                 if (commit) {
1395                         if (!(commit->object.flags & SEEN)) {
1396                                 commit->object.flags |= SEEN;
1397                                 insert_by_date(commit, &revs->commits);
1398                         }
1399                 }
1400                 e++;
1401         }
1402         free(list);
1403
1404         if (revs->no_walk)
1405                 return 0;
1406         if (revs->limited)
1407                 if (limit_list(revs) < 0)
1408                         return -1;
1409         if (revs->topo_order)
1410                 sort_in_topological_order(&revs->commits, revs->lifo);
1411         if (revs->children.name)
1412                 set_children(revs);
1413         return 0;
1414 }
1415
1416 enum rewrite_result {
1417         rewrite_one_ok,
1418         rewrite_one_noparents,
1419         rewrite_one_error,
1420 };
1421
1422 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1423 {
1424         struct commit_list *cache = NULL;
1425
1426         for (;;) {
1427                 struct commit *p = *pp;
1428                 if (!revs->limited)
1429                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
1430                                 return rewrite_one_error;
1431                 if (p->parents && p->parents->next)
1432                         return rewrite_one_ok;
1433                 if (p->object.flags & UNINTERESTING)
1434                         return rewrite_one_ok;
1435                 if (!(p->object.flags & TREESAME))
1436                         return rewrite_one_ok;
1437                 if (!p->parents)
1438                         return rewrite_one_noparents;
1439                 *pp = p->parents->item;
1440         }
1441 }
1442
1443 static void remove_duplicate_parents(struct commit *commit)
1444 {
1445         struct commit_list **pp, *p;
1446
1447         /* Examine existing parents while marking ones we have seen... */
1448         pp = &commit->parents;
1449         while ((p = *pp) != NULL) {
1450                 struct commit *parent = p->item;
1451                 if (parent->object.flags & TMP_MARK) {
1452                         *pp = p->next;
1453                         continue;
1454                 }
1455                 parent->object.flags |= TMP_MARK;
1456                 pp = &p->next;
1457         }
1458         /* ... and clear the temporary mark */
1459         for (p = commit->parents; p; p = p->next)
1460                 p->item->object.flags &= ~TMP_MARK;
1461 }
1462
1463 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1464 {
1465         struct commit_list **pp = &commit->parents;
1466         while (*pp) {
1467                 struct commit_list *parent = *pp;
1468                 switch (rewrite_one(revs, &parent->item)) {
1469                 case rewrite_one_ok:
1470                         break;
1471                 case rewrite_one_noparents:
1472                         *pp = parent->next;
1473                         continue;
1474                 case rewrite_one_error:
1475                         return -1;
1476                 }
1477                 pp = &parent->next;
1478         }
1479         remove_duplicate_parents(commit);
1480         return 0;
1481 }
1482
1483 static int commit_match(struct commit *commit, struct rev_info *opt)
1484 {
1485         if (!opt->grep_filter.pattern_list)
1486                 return 1;
1487         return grep_buffer(&opt->grep_filter,
1488                            NULL, /* we say nothing, not even filename */
1489                            commit->buffer, strlen(commit->buffer));
1490 }
1491
1492 static inline int want_ancestry(struct rev_info *revs)
1493 {
1494         return (revs->rewrite_parents || revs->children.name);
1495 }
1496
1497 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1498 {
1499         if (commit->object.flags & SHOWN)
1500                 return commit_ignore;
1501         if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
1502                 return commit_ignore;
1503         if (revs->show_all)
1504                 return commit_show;
1505         if (commit->object.flags & UNINTERESTING)
1506                 return commit_ignore;
1507         if (revs->min_age != -1 && (commit->date > revs->min_age))
1508                 return commit_ignore;
1509         if (revs->no_merges && commit->parents && commit->parents->next)
1510                 return commit_ignore;
1511         if (!commit_match(commit, revs))
1512                 return commit_ignore;
1513         if (revs->prune && revs->dense) {
1514                 /* Commit without changes? */
1515                 if (commit->object.flags & TREESAME) {
1516                         /* drop merges unless we want parenthood */
1517                         if (!want_ancestry(revs))
1518                                 return commit_ignore;
1519                         /* non-merge - always ignore it */
1520                         if (!commit->parents || !commit->parents->next)
1521                                 return commit_ignore;
1522                 }
1523                 if (want_ancestry(revs) && rewrite_parents(revs, commit) < 0)
1524                         return commit_error;
1525         }
1526         return commit_show;
1527 }
1528
1529 static struct commit *get_revision_1(struct rev_info *revs)
1530 {
1531         if (!revs->commits)
1532                 return NULL;
1533
1534         do {
1535                 struct commit_list *entry = revs->commits;
1536                 struct commit *commit = entry->item;
1537
1538                 revs->commits = entry->next;
1539                 free(entry);
1540
1541                 if (revs->reflog_info)
1542                         fake_reflog_parent(revs->reflog_info, commit);
1543
1544                 /*
1545                  * If we haven't done the list limiting, we need to look at
1546                  * the parents here. We also need to do the date-based limiting
1547                  * that we'd otherwise have done in limit_list().
1548                  */
1549                 if (!revs->limited) {
1550                         if (revs->max_age != -1 &&
1551                             (commit->date < revs->max_age))
1552                                 continue;
1553                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
1554                                 return NULL;
1555                 }
1556
1557                 switch (simplify_commit(revs, commit)) {
1558                 case commit_ignore:
1559                         continue;
1560                 case commit_error:
1561                         return NULL;
1562                 default:
1563                         return commit;
1564                 }
1565         } while (revs->commits);
1566         return NULL;
1567 }
1568
1569 static void gc_boundary(struct object_array *array)
1570 {
1571         unsigned nr = array->nr;
1572         unsigned alloc = array->alloc;
1573         struct object_array_entry *objects = array->objects;
1574
1575         if (alloc <= nr) {
1576                 unsigned i, j;
1577                 for (i = j = 0; i < nr; i++) {
1578                         if (objects[i].item->flags & SHOWN)
1579                                 continue;
1580                         if (i != j)
1581                                 objects[j] = objects[i];
1582                         j++;
1583                 }
1584                 for (i = j; i < nr; i++)
1585                         objects[i].item = NULL;
1586                 array->nr = j;
1587         }
1588 }
1589
1590 static void create_boundary_commit_list(struct rev_info *revs)
1591 {
1592         unsigned i;
1593         struct commit *c;
1594         struct object_array *array = &revs->boundary_commits;
1595         struct object_array_entry *objects = array->objects;
1596
1597         /*
1598          * If revs->commits is non-NULL at this point, an error occurred in
1599          * get_revision_1().  Ignore the error and continue printing the
1600          * boundary commits anyway.  (This is what the code has always
1601          * done.)
1602          */
1603         if (revs->commits) {
1604                 free_commit_list(revs->commits);
1605                 revs->commits = NULL;
1606         }
1607
1608         /*
1609          * Put all of the actual boundary commits from revs->boundary_commits
1610          * into revs->commits
1611          */
1612         for (i = 0; i < array->nr; i++) {
1613                 c = (struct commit *)(objects[i].item);
1614                 if (!c)
1615                         continue;
1616                 if (!(c->object.flags & CHILD_SHOWN))
1617                         continue;
1618                 if (c->object.flags & (SHOWN | BOUNDARY))
1619                         continue;
1620                 c->object.flags |= BOUNDARY;
1621                 commit_list_insert(c, &revs->commits);
1622         }
1623
1624         /*
1625          * If revs->topo_order is set, sort the boundary commits
1626          * in topological order
1627          */
1628         sort_in_topological_order(&revs->commits, revs->lifo);
1629 }
1630
1631 static struct commit *get_revision_internal(struct rev_info *revs)
1632 {
1633         struct commit *c = NULL;
1634         struct commit_list *l;
1635
1636         if (revs->boundary == 2) {
1637                 /*
1638                  * All of the normal commits have already been returned,
1639                  * and we are now returning boundary commits.
1640                  * create_boundary_commit_list() has populated
1641                  * revs->commits with the remaining commits to return.
1642                  */
1643                 c = pop_commit(&revs->commits);
1644                 if (c)
1645                         c->object.flags |= SHOWN;
1646                 return c;
1647         }
1648
1649         if (revs->reverse) {
1650                 int limit = -1;
1651
1652                 if (0 <= revs->max_count) {
1653                         limit = revs->max_count;
1654                         if (0 < revs->skip_count)
1655                                 limit += revs->skip_count;
1656                 }
1657                 l = NULL;
1658                 while ((c = get_revision_1(revs))) {
1659                         commit_list_insert(c, &l);
1660                         if ((0 < limit) && !--limit)
1661                                 break;
1662                 }
1663                 revs->commits = l;
1664                 revs->reverse = 0;
1665                 revs->max_count = -1;
1666                 c = NULL;
1667         }
1668
1669         /*
1670          * Now pick up what they want to give us
1671          */
1672         c = get_revision_1(revs);
1673         if (c) {
1674                 while (0 < revs->skip_count) {
1675                         revs->skip_count--;
1676                         c = get_revision_1(revs);
1677                         if (!c)
1678                                 break;
1679                 }
1680         }
1681
1682         /*
1683          * Check the max_count.
1684          */
1685         switch (revs->max_count) {
1686         case -1:
1687                 break;
1688         case 0:
1689                 c = NULL;
1690                 break;
1691         default:
1692                 revs->max_count--;
1693         }
1694
1695         if (c)
1696                 c->object.flags |= SHOWN;
1697
1698         if (!revs->boundary) {
1699                 return c;
1700         }
1701
1702         if (!c) {
1703                 /*
1704                  * get_revision_1() runs out the commits, and
1705                  * we are done computing the boundaries.
1706                  * switch to boundary commits output mode.
1707                  */
1708                 revs->boundary = 2;
1709
1710                 /*
1711                  * Update revs->commits to contain the list of
1712                  * boundary commits.
1713                  */
1714                 create_boundary_commit_list(revs);
1715
1716                 return get_revision_internal(revs);
1717         }
1718
1719         /*
1720          * boundary commits are the commits that are parents of the
1721          * ones we got from get_revision_1() but they themselves are
1722          * not returned from get_revision_1().  Before returning
1723          * 'c', we need to mark its parents that they could be boundaries.
1724          */
1725
1726         for (l = c->parents; l; l = l->next) {
1727                 struct object *p;
1728                 p = &(l->item->object);
1729                 if (p->flags & (CHILD_SHOWN | SHOWN))
1730                         continue;
1731                 p->flags |= CHILD_SHOWN;
1732                 gc_boundary(&revs->boundary_commits);
1733                 add_object_array(p, NULL, &revs->boundary_commits);
1734         }
1735
1736         return c;
1737 }
1738
1739 struct commit *get_revision(struct rev_info *revs)
1740 {
1741         struct commit *c = get_revision_internal(revs);
1742         if (c && revs->graph)
1743                 graph_update(revs->graph, c);
1744         return c;
1745 }